Health Hazards
Once released into the environment, PCBs do not breakdown and are therefore have found their way into many ecosystems finally accumulating in plants, animals and human beings. The import, manufacture, and sale of PCBs were made illegal in Canada in 1977. The goal of the legislation has been to eliminate PCBs entirely but the widespread use and the difficulty to destroy them had created an ongoing problem in meeting this goal. Total elimination of PCBs from Canada may not be reached for another generation.
Among the health affects of PCB's are skin ailments called chloracne, reproductive disorders, liver disease and neurological problems in children. Some studies indicate that PCBs are associated with certain kinds of cancer in humans, such as cancer of the liver and biliary tract.
Disposal
The most effective means of destroying PCBs is through incineration. Although PCBs do not themselves ignite, they can be combusted under extreme heat and carefully controlled conditions. Current regulations require that PCBs are burnt at a temperature of 1200ºC for at least two seconds, in the presence of fuel oil and excess oxygen. A lack of oxygen can result in the formation of PCDDs, PCDFs and dioxins, or the incomplete destruction of the PCBs. Such specific conditions mean that it is extremely expensive to destroy PCBs on a tonnage scale, and it can only be used on PCB containing equipment and contaminated liquid. There are several thousand storage facilities across the country housing PCBs awaiting destruction.
Sources & Further Information
Environment Canada
Environment Canada (PCB fact sheets)
Wikipedia